package com.zyx.strategy.stg02;

import java.util.Map;

import lombok.extern.slf4j.Slf4j;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.lang.NonNull;
import org.springframework.stereotype.Component;


/**
 * <p>获取javabean工具类
 * <p>reference: https://www.cnblogs.com/a393060727/p/6110699.html
 *
 * @author Yaxi.Zhang
 * @since 2022/10/9 23:01
 */
@Component
@Slf4j
public class SpringContextHolder implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    /**
     * 实现ApplicationContextAware接口的context注入函数, 将其存入静态变量
     */
    public void setApplicationContext(@NonNull ApplicationContext applicationContext) {
        SpringContextHolder.applicationContext = applicationContext;
    }

    /**
     * 取得存储在静态变量中的ApplicationContext
     */
    public static ApplicationContext getApplicationContext() {
        checkApplicationContext();
        return applicationContext;
    }

    /**
     * 从静态变量ApplicationContext中取得Bean, 自动转型为所赋值对象的类型.
     */
    @SuppressWarnings("unchecked")
    public static <T> T getBean(String name) {
        checkApplicationContext();
        if (applicationContext == null) {
            return null;
        }
        return (T) applicationContext.getBean(name);
    }

    /**
     * 从静态变量ApplicationContext中取得Bean, 自动转型为所赋值对象的类型
     * 如果有多个Bean符合Class, 取出第一个
     */
    @SuppressWarnings("unchecked")
    public static <T> T getBean(Class<T> clazz) {
        checkApplicationContext();
        @SuppressWarnings("rawtypes")
        Map beanMaps = applicationContext.getBeansOfType(clazz);
        if (!beanMaps.isEmpty()) {
            return (T) beanMaps.values().iterator().next();
        } else {
            return null;
        }
    }

    private static void checkApplicationContext() {
        if (applicationContext == null) {
            throw new IllegalStateException("applicationContext未注入,请在applicationContext.xml中定义SpringContextHolder");
        }
    }

}
